Seasonality of hypercalcemia - A population-based study on patients with pulmonary sarcoidosis

Introduction: Hypercalcemia is a well-known complication of pulmonary sarcoidosis, which occurs in 5-10% of patients. Pulmonary alveolar macrophages express 1-alphahydroxylase, the enzyme responsible for the conversion of excess active vitamin D. Previous studies indicate seasonality of the incidence of sarcoidosis and vitamin D.Objective: This study aimed to investigate potential seasonal variation of hypercalcemia in patients with pulmonary sarcoidosis living on the island Funen, Denmark. We also examined the incidence of pulmonary sarcoidosis.Method: The study population was selected form the Funen Laboratory Cohort, which consists of residents living on Funen (490.973 in 2015), who had a creatinine measurement between January 2000 and December 2015. Patients with an ICD10 code of pulmonary sarcoidosis, living on Funen at the time of diagnosis and one year prior, were included. The study period was dependent on the sun data acquired from the Danish Metrological Institute and was consequently from 2004-2015.Results: The study included 787 patients with pulmonary sarcoidosis. Hypercalcemia was present in 127 patients with pulmonary sarcoidosis, compatible with a prevalence of 15.9%. The incidence of hypercalcemia increased during summer months, with a peak from April to September. The average incidence of pulmonary sarcoidosis throughout the study period was 13.6 per 100.000 person-years.Conclusion: We found an association between hypercalcemia in patients with pulmonary sarcoidosis and seasonality. This knowledge may have implications on how physicians should inform and instruct the patients in order to prevent development of potential symptomatic hypercalcemia requiring treatment.FootnotesCite this article as: European Respiratory Journal 2021; 58: Suppl. 65, PA705.This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).